Possible oxygenation problem?

I've had my 12g nano-cube for almost a month, and it is fully-cycled with live sand and live rock. I just added my first fish, an ocelaris clown. He is eating well, but I'm worried about the way he is behaving. He always seems to be active, constantly swimming around the edges of the tank, almost frantically. He seems to be fighting the current quite a bit when in reality he could just chill out in the rocks or out of the current. Sometimes he also swims at the surface as if he needs more air or something.

My question regards oxygenation. Could the oxygen levels possibly be too low in the tank? Do I need an air-stone in the tank? I initially thought the flow from the water pump would allow for enough oxygen exchange (from the surface,) but now I'm starting to think that it's not enough. Any thoughts?

Also, I'm trying to figure out the best direction to point the pump outlet. Should it point toward the surface to allow better oxygenation? Should it point straight out toward the glass? Or toward the center of the tank? I don't want my fish to be constantly fighting the current... :b9:

Do you have a sump? skimmer? I have my powerheads set up in a way to create surface agitation, but not so much that it splashes my lights. An air stone would be too messy with a saltwater tank. How long have you had the clown, and what exactly do you have for water movement?

Do you have a sump? skimmer? I have my powerheads set up in a way to create surface agitation, but not so much that it splashes my lights. An air stone would be too messy with a saltwater tank. How long have you had the clown, and what exactly do you have for water movement?

I don't have a sump or skimmer. The only thing moving water is the pump in the back, which does move quite a bit of water, but may not be providing enough aeration. Would a skimmer help? Are there any skimmers that fit inside the compartments in the back of the nano cube?